Air-brake system.



No. 762,177. PATENTEDI JUNE 7, 1904.

J. LOFTUS.

AIR BRAKE SYSTEM.

- APPLICATION FILED SEPT. 22. 1903.

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AIR BRAKE SYSTEM.

APPLICATION FILED SEPT. 22. 1908.

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PATENTED JUNE 7, 1904.

Patented June '7, 1904.

UNITED STATES PATENT OFFICE.

JOHN LOFTUS, OF ALBANY, NEIV YORK, ASSIGNOR OF ONE-HALF TO STANTON REDIOK, OF ALBANY, NEIV YORK.

AIR-BRAKE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 762,177, dated June 7, 1904.

Application filed September 22, 1903. Serial No. 174,200- (No model.)

T 0 all whom, it may concern.

Be it known that I, J OHN LOFTUS, a citizen of the United States, residing at Albany, in the county of Albany and State of New York, have invented new and useful Improvements in Air-Brake Systems, of which the following is a specification.

This invention relates to automatic air-brake systems for railroad-trains, and is intended to remedy a defect incident to the lapse of time required to release the brakes on the rear part of a train as compared to the engine or front part thereof.

In long trains, particularly long freighttrains, it is known that when the brakes are set and it is desired to release them the brakes on the rear cars are slow to release, because of the time required to restore the train-pipe pressure from the mainreservoir. Naturally the brakes on the cars nearest the engine are first released. The result and defect of this is that the head of the train surges ahead until checked by the unreleased brakes on the rear cars, causing a strain on the couplings, which frequently results in breaking the coupling or pulling out draw-heads, so that it is sometimes now necessary to stop the train until all the brakes are released. To remedy this defect, I provide means, in short, for holding the brakes on the engine or tender until all the car-brakes shall have been released, causing the cars to push against the engine and compress the bumper-springs if the train be moving, or, in any event, making a free train for the start or pull of the engine. The means to produce this result are under control of the engineer by means of a modification and manipulation of the engineers brake-valve, as hereinafter described, whereby the exhaust from the triple valve of the tender is prevented, holding the brakes thereon until all the cars are free. At present the engineers rotary brake-valve contains a small warning or alarm port, which when the valve is at full-release position opens communication from the main reservoir to atmosphere, so that the noise of the escaping air will-attract the attention of the engineer and lessen the chances of his forgetting to return valve to running position. I connect this outlet to the exhaust from the tender triple valve, so that when the valve is first thrown to full-release position the excess pressure on the upper side of a disk valve, which I employ, prevents the exhaust of air therefrom, and consequently holds the brakes in set position until further movement of the engineers valve. Means are also provided for preventing this action in case quick release of the tender-brakes is desired.

In the accompanying drawings, Figure 1 is an elevation of the air-brake apparatus of an engine and tender with my invention applied thereto partly in section. Fig. 2 is a vertical sectional view through the valve and its 5 seat. Fig. 3 is a'face view of the rotary valve. Fig. 4 is a face view of its valve-seat.

Referring specifically to the drawings, the well-known parts of the apparatus are indicated as follows: 6 is the main reservoir, 7 is 7 the equalizing-reservoir, 8 is the engineers brake-valve, 9 is the train-pipe, and 10 is the triple valve of the tender. The exhaust from the latter instead of opening to the atmosphere opens to a pipe 11, connected to one side of a valve-casing 12, the other side of which is connected by a pipe 13 to the engineers valve. The pipe 11 has a relief-cock 11. Said casing is preferably located adjacent to the engineers valve and contains a disk valve 14, adapted to seat over an opening in the diaphragm 15 in the valve-casing. The valve-stem 16 is extended in both directions to .open and close ports 17 and 18 on opposite sides of the diaphragm, and in operation the port 17 acts as s the warning-port from the engineers valve and the port 18 to permit exhaust from the triple valve.

At 19 is indicated the warning-port in the engineers valve, open to air from the main 9 reservoir. Instead of the usual port to atmosphere with which this port registerswhen the handle is in full-release position I connect said port with the pipe 13 by means of a small port 20, bored in a lip 21, which projects from the bridge of the valve-seat into the main exhaust-cavity 22 of the valve-seat 23. This lip is of less width than the main exhaust-cavity. The port 19 registers with the port 20 when the valve is in full-release position, and thereby admits main-reservoir pressure to the pipe 13 and top of the valve 14.

In operation, assuming that the brakes on p the train are set, the valve 8 is moved to fullrelease position. The air in main reservoir will then discharge into the train-line and release the brakes, but at the same time the main reservoir pressure will pass through ports 19 and 20 and pipe 13, creating an excess of pressure on the valve 1 1, which will hold said valve closed and also port 18, and thus retainexcess pressure in the pipe 11 behind the triple valve of the tender and prevent exhaust therefrom, thereby holding the brakes on the tender. At the same time the small quantity of air escapes slowly through the port 17, which thus becomes the warning-port, showing that the handle is in full-release position. When suflicient time has elapsed for all the car-brakes to come to release, the engineer turns his valve to running position, as usual. This cuts off the port 20 and pipe 13 from the main reservoir, and the air above the valve 14 escaping through port 17 creates a deficiency of pressure, which allows the valve 14:

to lift, opening the port 18 and permitting exhaust from the triple valve and release of the brakes on the tender. Thus said brakes are the last in the train to release, so that the cars pile up against the tender. If the engine is running light or if for any other reason it IS not desired to produce this eflect, the

relief-cock 11, which is of greater capacity than the port 17, is opened, allowing free Having thus fully described the invention, what is claimed as new is 1. In an air-brake system, the combination with a triple valve, and an engineers valve; of means controlled by the main-reservoir pressure to prevent exhaust from the triple valve, said means comprising a casing having exhaust and warning ports, and a valve in the casing controlling said ports and receiving on opposite sides thereof the exhaustpressure from the triple valve and the mainreservoir pressure from the engineers valve.

2. In an air-brake system, the combination with a triple valve, a main reservoir, a connecting-pipe between the same, and an engineers valve in said pipe, of means'controlled by said latter valve, when in full-release position, to counterbalance train-pipe pressure on the triple valve, said means comprising acasing having exhaust and warning ports,and a valve inthe casing controlling said ports and receiving on opposite sides thereof the exhaust-pressure from the triple valve and the main-reservoir pressurefrom the engineers valve.

3. In an air-brake system, the combination with the main reservoir, a triple valve, a trainpipe connecting the same, and an engineers valve in the train-pipe, of a pipe connecting the triple valve and the engineers valve, a casing in said pipe having exhaust and warning ports, and a valve in said casing controlling both ports and receiving on opposite sides the exhaust-pressure from the triple valve and the main-reservoir pressure from the engineers valve, when in full-release position.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN LOFTUS.

WVitnesses:

PETER KINNEAR, LEWIS DEITZ. 

